The subject matter disclosed herein relates to a pump assembly and, more particularly, to a pump assembly with a charge pump rotor, an inversion pump rotor and a scavenge pump rotor.
A pump is a device that moves fluids (liquids or gases) or sometimes slurries by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid. These include direct lift, displacement and gravity pumps. A displacement pump (or a positive displacement pump) makes a fluid move by trapping a fixed amount and forcing or displacing that trapped volume into a discharge pipe. Some positive displacement pumps use an expanding cavity on a suction side and a decreasing cavity on the discharge side. Liquid flows into the pump as the cavity on the suction side expands and the liquid flows out of the discharge as the cavity collapses. The volume is constant through each cycle of operation.
A positive displacement pump can be further classified according to the mechanism used to move the fluid into rotary type positive displacement pumps, reciprocating type positive displacement pumps and linear type positive displacement pumps. Rotary type positive displacement pumps move fluid using a rotating mechanism that creates a vacuum or low pressure region that captures and draws in fluid and then creates a high pressure region that forces that fluid into the discharge pipe.